LOLIN S2 Mini

by Wemos

Image of Board

The LOLIN S2 Mini is a small (33.4 mm x 25.4 mm) development board. The form factor is almost the same as the well-known LOLIN D1 mini. This means that there is a high chance that the D1 Mini Shields could also be uses with this board.

Technical details

  • ESP32-S2FN4R2 WiFi SoC
    • Xtensa® single-core 32-bit LX7 microprocessor, up to 240 MHz
    • Integrated 802.11 b/g/n WiFi 2.4 GHz Transceiver, up to 150 Mbps
    • Integrated RISC-V ULP Coprocessor
    • Integrated Temperature Sensor (-20 °C to 110 °C)
    • Operating Voltage: 3.0 to 3.6 V
      • WiFi: 310 mA (peak)
      • Modem-sleep: 12-19 mA
      • Light-Sleep: 450 µA
      • Deep-Sleep: 20-190 µA
    • 320 KB SRAM
    • 4 MB Flash (embedded)
    • 2 MB PSRAM (embedded)
    • 16 KB SRAM in RTC (accessable by main CPU, 8 KB accessable by ULP coprocessor)
    • 4 Kbit eFuse (1792 bits reserved for user data)
    • 2 13-bit SAR ADCs, up to 20 channels (2 channels not available on ADC2 due to USB D+/D-)
      • 2 8-bit DAC
      • 14 touch sensing IOs
      • 4 SPI (2 usable due to embedded flash & PSRAM)
      • 1 I2S
      • 2 I2C
      • 2 UART
      • 1 DVP 8/16 camera interface, implemented using the hardware resources of I2S
      • 1 LCD interface (8-bit serial RGB/8080/6800), implemented using the hardware resources of SPI2
      • 1 LCD interface (8/16/24-bit parallel), implemented using the hardware resources of I2S
      • 1 TWAI® controller compatible with ISO 11898-1 (CAN Specification 2.0)
      • LED PWM controller, up to 8 channels
      • USB OTG 1.1 controller and PHY, with host and device support
      • Cryptographic Hardware Accelerators: AES, ECB/CBC/OFB/CFB/CTR, GCM, SHA, RSA, ECC (Digital Signature)
  • USB-C connector, for built-in ROM USB bootloader, serial port debugging, and USB device mode
  • 3.3 V regulator ME6211C33
    • Maximum Output Current: 500 mA (VIN=4.3 V, VOUT=3.3 V)
    • Dropout Voltage: 100 mV@ IOUT=100 mA
    • Operating Voltage Range: 2V~6.0V
    • Low Power Consumption: 40 µA (typ.)
    • Standby Current: 0.1 µA (typ.)
  • 27 GPIO pins, plus EN, VBUS, 3V3, GND, GND
    • 16 pins (outer) compatible with WEMOS/LOLIN D1 mini shields
    • EN RESET button
    • GPIO0 BOOT button
    • GPIO15 LED (blue status LED)
  • Compatible with CircuitPython, MicroPython (default firmware), Arduino and ESP-IDF

Notes

  • There is an error on the v1.0.0 board silkscreen. GPIO12/13 should be reversed. Error is fixed without version change since late 2021.

Learn More

Enter bootloader

To enter UF2 Bootloader Version 0.10.2:

  • Click reset button
  • Wait until LED is lit
  • Hold BOOT button

Be sure not to hold BOOT button when RESET button is pressed.

Purchase

Contribute

Have some info to add for this board? Edit the source for this page here.

CircuitPython 9.0.5

This is the latest stable release of CircuitPython that will work with the LOLIN S2 Mini.

Use this release if you are new to CircuitPython.

Release Notes for 9.0.5

Built-in modules available: _asyncio, _pixelmap, adafruit_bus_device, adafruit_pixelbuf, aesio, alarm, analogbufio, analogio, array, atexit, audiobusio, audiocore, audiomixer, binascii, bitbangio, bitmaptools, board, builtins, builtins.pow3, busdisplay, busio, busio.SPI, busio.UART, canio, codeop, collections, countio, digitalio, displayio, dualbank, epaperdisplay, errno, espcamera, espidf, espnow, espulp, fontio, fourwire, framebufferio, frequencyio, getpass, gifio, hashlib, i2cdisplaybus, io, ipaddress, jpegio, json, keypad, keypad.KeyMatrix, keypad.Keys, keypad.ShiftRegisterKeys, locale, math, mdns, memorymap, microcontroller, msgpack, neopixel_write, nvm, onewireio, os, os.getenv, paralleldisplaybus, ps2io, pulseio, pwmio, qrio, rainbowio, random, re, rgbmatrix, rotaryio, rtc, sdcardio, select, sharpdisplay, socketpool, ssl, storage, struct, supervisor, synthio, sys, terminalio, time, touchio, traceback, ulab, usb_cdc, usb_hid, usb_midi, vectorio, warnings, watchdog, wifi, zlib

Included frozen(?) modules: neopixel

CircuitPython 9.1.0-beta.3

This is the latest development release of CircuitPython that will work with the LOLIN S2 Mini.

Alpha development releases are early releases. They are unfinished, are likely to have bugs, and the features they provide may change. Beta releases may have some bugs and unfinished features, but should be suitable for many uses. A Release Candidate (rc) release is considered done and will become the next stable release, assuming no further issues are found.

Please try alpha, beta, and rc releases if you are able. Your testing is invaluable: it helps us uncover and find issues quickly.

Release Notes for 9.1.0-beta.3

Built-in modules available: _asyncio, _pixelmap, adafruit_bus_device, adafruit_pixelbuf, aesio, alarm, analogbufio, analogio, array, atexit, audiobusio, audiocore, audiomixer, audiomp3, binascii, bitbangio, bitmaptools, board, builtins, builtins.pow3, busdisplay, busio, busio.SPI, busio.UART, canio, codeop, collections, countio, digitalio, displayio, epaperdisplay, errno, espcamera, espidf, espnow, espulp, fontio, fourwire, framebufferio, frequencyio, getpass, gifio, hashlib, i2cdisplaybus, io, ipaddress, jpegio, json, keypad, keypad.KeyMatrix, keypad.Keys, keypad.ShiftRegisterKeys, keypad_demux, keypad_demux.DemuxKeyMatrix, locale, math, max3421e, mdns, memorymap, microcontroller, msgpack, neopixel_write, nvm, onewireio, os, os.getenv, paralleldisplaybus, ps2io, pulseio, pwmio, qrio, rainbowio, random, re, rgbmatrix, rotaryio, rtc, sdcardio, select, sharpdisplay, socketpool, ssl, storage, struct, supervisor, synthio, sys, terminalio, time, touchio, traceback, ulab, usb, usb_cdc, usb_hid, usb_midi, vectorio, warnings, watchdog, wifi, zlib

Included frozen(?) modules: neopixel

Absolute Newest

Every time we commit new code to CircuitPython we automatically build binaries for each board and language. The binaries are stored on Amazon S3, organized by board, and then by language. These releases are even newer than the development release listed above. Try them if you want the absolute latest and are feeling daring or want to see if a problem has been fixed.

Previous Versions of CircuitPython

All previous releases of CircuitPython are available for download from Amazon S3 through the button below. For very old releases, look in the OLD/ folder for each board. Release notes for each release are available at GitHub button below.

Older releases are useful for testing if you something appears to be broken in a newer release but used to work, or if you have older code that depends on features only available in an older release. Otherwise we recommend using the latest stable release.

Install, Repair, or Update UF2 Bootloader

Latest version: 0.18.2

The UF2 bootloader allows you to load CircuitPython, MakeCode, and Arduino programs. The bootloader is not CircuitPython. If a UF2 bootloader is installed, you can check its version by looking in the INFO_UF2.TXT file when the BOOT drive is visible (FTHRS2BOOT, MAGTAGBOOT, HOUSEBOOT, etc.)

It is not necessary to reinstall a UF2 bootloader you unless a BOOT drive is not visible when in UF2 bootloader mode, or you know of a problem with your current UF2 bootloader.

If a UF2 bootloader has never been installed on the board, or the UF2 bootloader was removed by erasing or overwriting the flash, the UF2 bootloader must be installed in order to flash .uf2 files onto the board. .bin files can be uploaded without a UF2 bootloader, using the ESP Web Flasher or esptool.py.

Note: update.uf2 files are not currently working on ESP32-S2 or ESP32-S3 boards.

Important: this will erase previously flashed firmware and sketches from the board, but needs to be perfomed only once.

The instructions here are general. We recommend you consult the manufacturer's board documentation for detailed instructions, which may be different.

  • Unzip to find the file combined.bin.
  • Place board in bootloader mode:
    • Plug board into a USB port on your computer using a data/sync cable. Make sure it is the only board plugged in, and that a charge-only cable is not being used.
    • Press and hold down the BOOT or 0 button.
    • Press and release the RESET or RST button.
    • Release the BOOT button.
  • Upload combined.bin (Google Chrome 89 or newer):
    • Open ESP Web Flasher in a new window/tab.
    • Select 460800 Baud from the pull-down menu (top-right).
    • Click Connect (top-right).
    • Select the COM or Serial port from the pop-up window.
    • After successful connection, click Erase.
    • After successful erase, click any Choose a file..., then locate and select the combined.bin file unzipped earlier.
    • After successfully choosing combined.bin, click Program.
    • After the TinyUF2 firmware update is complete, press the RESET button on the board. A new drive BOOT should be visible in your file browser.

After installing the UF2 bootloader, enter the bootloader by double-clicking the reset button. On boards with an RGB status LED, tap reset once, wait for the LED to turn purple, and tap again before the purple goes away. On other boards, consult the board documentation.

After you update, check INFO_UF2.TXT to verify that the bootloader version has been updated. Then you will need to load or reload CircuitPython using the .uf2 file.